In analogy to recent hypertriton measurements [1]}, [2]} we focus here on the expected two-body decay \(\overline{ \Lambda \mathrm {n}} \rightarrow \overline{\mathrm {d}} \pi ^{+}\) .
For the data analysis the following strategy is used: first displaced vertices are identified using ITS and TPC information. In a second step the negative track of the \(V^{0}\)  candidate is identified as an anti-deuteron via the TPC \(\mathrm {d}E/\mathrm {d}x \)  information. If the second daughter is identified as a pion, the invariant mass of the pair is reconstructed. Both particles are required to lie within a 3 standard deviations (\(\sigma \) ) band of the expected Bethe-Bloch lines of the corresponding particles.
To identify the secondary vertex the two daughter tracks have to have a DCA smaller than 0.3 cm. Another condition is that the maximum pointing angle is smaller than 0.045 rad (see description above). Deuterons are cleanly identified in the rigidity region of 400 MeV/\(c\)  to 1.75 GeV/\(c\) . To limit contamination from other particle species, the d\(E\) /d\(x\)  has to be above 110 units of the TPC signal, shown in Fig. 1.
